Drill bits manufactured with copper nickel manganese alloys

ABSTRACT

A drill bit formed of a binder comprising a copper nickel manganese alloy is disclosed. The binder has an increased content of manganese, which improves the strength and toughness of the drill bit. Manganese forms a solid solution with copper in the alloy, as well as forming an intermetallic with the nickel constituent. The formation of the MnNi inter-metallic also serves to improve the erosion resistance of the binder alloy and thus the overall erosion resistance of the MMC.

TECHNICAL FIELD

The present disclosure relates generally to drilling tools, such as earth-boring drill bits, and more particularly, to metal-matrix composite (MMC) body drill bits having copper nickel manganese alloy based binders.

BACKGROUND

Various types of drilling tools including, but not limited to, rotary drill bits, reamers, core bits, under reamers, hole openers, stabilizers, and other downhole tools are used to form wellbores in downhole formations. Over the past several decades, there have been advances in the materials used to form drill bits. The cutting elements or cutters as they are sometimes called were once formed of natural diamond substances. Because of cost and other reasons, the industry sought alternative materials. In the mid-to-late 1970's, advances in synthetic diamond materials enabled the industry to replace natural diamond cutters with synthetic diamond cutters. The most common synthetic diamond that is used is a polycrystalline diamond material. These materials are formed into discs also known as compacts. Drill bits which use such synthetic diamond cutters are commonly referred to as polycrystalline diamond compact (PDC) bits.

There are two basic structures that are used in forming the bodies of PDC bits onto which the synthetic diamond cutters are affixed. The two such structures are known as matrix bodies or metal-matrix composite (MMC) bodies and steel-bodies. Both structures have their own advantages. Selecting which structure to use often depends on the needs of the particular application.

MMC drill bits are bits whose body is formed of a very hard, often brittle composite material, which comprises tungsten carbide grains metallurgically bonded with a softer tougher, metallic binder sometimes referred to as the universal binder. MMC drill bits are desirable because their hardness makes them resistant to abrasion and erosion. They are also capable of withstanding relatively high compressive loads, but they have (as compared to steel-body bits) low resistance to impact loading. Ever since matrix materials were first used in bit bodies, the industry has sought to improve the performance characteristics of these materials. One critical component in that quest has been the selection of the universal binder material. It has been found that sometimes minor changes in the formulation of the universal binder can have a significant impact on the performance of the bit bodies and thus drill bits themselves.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a drilling system which is capable of using a drill bit formed in accordance with the present disclosure;

FIG. 2 is an isometric view of a rotary drill bit oriented upwardly in a manner often used to model or design fixed-cutter drill bits and in which the material composition disclosed herein may be used;

FIG. 3 is a flow chart of an example method of forming an MMC drill bit body according to the present disclosure; and

FIG. 4 is a schematic diagram showing a mold and the material components of the metal matrix composite bit body which are placed in the mold as part of the formation of the bit body shown in FIG. 2 in accordance with the present disclosure.

DETAILED DESCRIPTION

According to various system and methods disclosed herein, the materials used to form the MMC bit body may include a universal binder which comprises a copper manganese nickel alloy. The present disclosure is directed to such alloys in the high manganese region of the CuMnNi alloy system. Investigation of the material properties of the universal binder has shown that increasing the percentage of manganese can improve the strength and toughness of the fixed cutter drill bit. Manganese forms a solid solution with copper in the alloy, as well as forming an intermetallic with the nickel constituent. Increased manganese content depresses the melt temperature of the system, and this allows alloys in this range to be melted using conventional furnaces.

The present disclosure may be understood with reference to FIGS. 1 through 4, where like numbers are used to indicate like and corresponding parts. FIG. 1 is an elevation view of a drilling system. Drilling system 100 may include a well surface or well site 106. Various types of drilling equipment such as a rotary table, drilling fluid pumps and drilling fluid tanks (not expressly shown) may be located at well surface or well site 106. For example, well site 106 may include drilling rig 102 that may have various characteristics and features associated with a land drilling rig. However, downhole drilling tools incorporating teachings of the present disclosure may be satisfactorily used with drilling equipment located on offshore platforms, drill ships, semi-submersibles, and/or drilling barges (not expressly shown).

Drilling system 100 may include drill string 103 associated with drill bit 101 that may be used to form a wide variety of wellbores or bore holes such as generally vertical wellbore 114 a or generally horizontal wellbore 114 b or any combination thereof. Various directional drilling techniques and associated components of bottom-hole assembly (BHA) 120 of drill string 103 may be used to form horizontal wellbore 114 b. For example, lateral forces may be applied to BHA 120 proximate kickoff location 113 to form generally horizontal wellbore 114 b extending from generally vertical wellbore 114 a. The term directional drilling may be used to describe drilling a wellbore or portions of a wellbore that extend at a desired angle or angles relative to vertical. Such angles may be greater than normal variations associated with vertical wellbores. Direction drilling may include horizontal drilling.

Drilling system 100 may also include drill bit 101. Drill bit 101, discussed in further detail in FIG. 2, may be an MMC drill bit which may be formed by placing loose reinforcement particles/material including tungsten carbide powder, into a mold and infiltrating the reinforcing particles with a universal binder material formed of a copper, manganese and nickel. The mold may be formed by milling a block of material, such as graphite, to define a mold cavity having features that correspond generally with the exterior features of drill bit 101.

Drill bit 101 may include one or more blades 126 that may be disposed outwardly from exterior portions of rotary bit body 124 of drill bit 101. Rotary bit body 124 may be generally cylindrical and blades 126 may be any suitable type of projections extending outwardly from rotary bit body 124. Drill bit 101 may rotate with respect to bit rotational axis 104 in a direction defined by directional arrow 105. Blades 126 may include one or more cutters 128 disposed outwardly from exterior portions of each blade 126. Blades 126 may further include one or more gage pads (not expressly shown) disposed on blades 126. Drill bit 101 may be designed and formed in accordance with teachings of the present disclosure and may have many different designs, configurations, and/or dimensions according to the particular application of drill bit 101.

FIG. 2 is an isometric view of a rotary drill bit oriented upwardly in a manner often used to model or design fixed-cutter drill bits. Drill bit 101 may be designed and formed in accordance with teachings of the present disclosure.

During a subterranean operation, different regions of drill bit 101 may be exposed to different forces and/or stresses. Therefore, during manufacturing of drill bit 101, the properties of drill bit 101 may be customized such that some regions of drill bit 101 may have different properties from other regions of drill bit 101. The localized properties may be achieved by placing a binder-reinforcing material (e.g., localized binder material) in selected locations and in selected configurations in a mold for drill bit 101. The type, location, and/or configuration of the localized binder-reinforcing material may be selected to provide localized properties for drill bit 101 based on the downhole conditions experienced by the region of drill bit 101 and/or the function of the region of drill bit 101. The present disclosure, however, is directed more specifically to the alloy which makes up the universal binder. The universal binder infiltrates the entire bit body and forms the matrix of the resulting metal-matrix composite material. The binder-reinforcing material (e.g., localized binder material), along with the reinforcement particles, are infiltrated and encapsulated by the universal binder.

Drill bit 101 may be an MMC drill bit which may be formed by placing loose reinforcement particles, including tungsten carbide powder, into a mold and infiltrating the reinforcing particles with a universal binder material. In the present disclosure, the universal binder is the alloy disclosed herein. The drill bit 101 may also have selected/localized areas of reinforced binder zones, especially in those areas subject to high stress.

The mold may be formed by milling a block of material, such as graphite, to define a mold cavity having features that correspond generally with the exterior features of drill bit 101. Various features of drill bit 101 including blades 126, cutter pockets 166, and/or fluid flow passageways may be provided by shaping the mold cavity and/or by positioning temporary displacement materials within interior portions of the mold cavity. A preformed steel shank or bit mandrel (sometimes referred to as a blank) may be placed within the mold cavity to provide reinforcement for bit body 124 and to allow attachment of drill bit 101 with a drill string and/or BHA. A quantity of reinforcement particles may be placed within the mold cavity and infiltrated with a molten universal binder material to form bit body 124 after solidification of the universal binder material with the reinforcement particles.

Drill bit 101 may include shank 152 with drill pipe threads 155 formed thereon. Threads 155 may be used to releasably engage drill bit 101 with a bottom-hole assembly (BHA), such as BHA 120, shown in FIG. 1, whereby drill bit 101 may be rotated relative to bit rotational axis 104. Plurality of blades 126 a-126 g may have respective junk slots or fluid flow paths 140 disposed there between. Due to erosion during a subterranean operation, drill bit 101 may have a localized binder-reinforcing material placed near junk slots 140 to provide further erosion resistance. The binder-reinforcing material may be selected to reduce the surface energy in junk slots 140 to provide optimized fluid flow through junk slots 140.

Drilling fluids may be communicated to one or more nozzles 156. The regions of drill bit 101 near nozzle 156 may be subject to stresses during the subterranean operation that may cause cracks in drill bit 101. A localized binder-reinforcing material may be added near nozzles 156 to increase the strength of resilience and provide crack-arresting properties near nozzles 156 of drill bit 101. The localized binder-reinforcing material may be selected to reduce the surface energy near nozzles 156 to provide optimized flow of drilling fluids through nozzles 156.

Drill bit 101 may include one or more blades 126 a-126 g, collectively referred to as blades 126, which may be disposed outwardly from exterior portions of rotary bit body 124. Rotary bit body 124 may have a generally cylindrical body and blades 126 may be any suitable type of projections extending outwardly from rotary bit body 124. For example, a portion of blade 126 may be directly or indirectly coupled to an exterior portion of bit body 124, while another portion of blade 126 may be projected away from the exterior portion of bit body 124. Blades 126 formed in accordance with the teachings of the present disclosure may have a wide variety of configurations including, but not limited to, substantially arched, helical, spiraling, tapered, converging, diverging, symmetrical, and/or asymmetrical.

Blades 126 may include one or more cutters 128 disposed outwardly from exterior portions of each blade 126. For example, a portion of cutter 128 may be directly or indirectly coupled to an exterior portion of blade 126 while another portion of cutter 128 may be projected away from the exterior portion of blade 126. Cutters 128 may be any suitable device configured to cut into a formation, including but not limited to, primary cutters, back-up cutters, secondary cutters, or any combination thereof. By way of example and not limitation, cutters 128 may be various types of cutters, compacts, buttons, inserts, and gage cutters satisfactory for use with a wide variety of drill bits 101.

Cutters 128 may include respective substrates with a layer of hard cutting material, including cutting table 162, disposed on one end of each respective substrate, including substrate 164. The cutters 128 are arranged such that the cutting tables 162 are aligned on the leading surface 130 of the blades 126. Blades 126 may include recesses or cutter pockets 166 that may be configured to receive cutters 128. For example, cutter pockets 166 may be concave cutouts on blades 126. Cutter pockets 166 may be subject to impact forces during the subterranean operation. Therefore, a localized binder material may be used to provide impact toughness to cutter pockets 166. Additionally, localized binder material may be used to increase the surface energy of cutter pockets 166 to assist in increasing bonding adhesion. Further, localized binder material may be used to produce rougher surfaces in cutter pockets 166, providing mechanical interlocking during the brazing process when cutters 128 are coupled to cutter pockets 166.

Drill bits, such as drill bit 101, may be formed using a mold assembly. FIG. 3 is a flow chart of an example method of forming a metal-matrix composite drill bit utilizing the universal binder in accordance with the present disclosure. The steps of method 300 may be performed by a person or manufacturing device (referred to as a manufacturer) that is configured to fill molds used to form MMC drill bits.

Method 300 may begin at step 302 (or alternatively at step 304 described below) where the manufacturer may place reinforcement particles, such as a tungsten carbide powder in a matrix bit body mold. In one embodiment, binder-reinforcing material may be placed in layers in localized regions of the bit body needing greater toughness, erosion resistance and other preferential properties.

The reinforcement particles/material may be selected to provide designed characteristics for the resulting drill bit, such as fracture resistance, toughness, and/or erosion, abrasion, and wear resistance. The reinforcing particles may be any suitable material, such as, but are not limited to, particles of metals, metal alloys, super alloys, intermetallics, borides, carbides, nitrides, oxides, silicides, ceramics, diamonds, and the like, or any combination thereof. More particularly, examples of reinforcing particles suitable for use in conjunction with the embodiments described herein may include particles that include, but are not limited to, tungsten, molybdenum, niobium, tantalum, rhenium, iridium, ruthenium, beryllium, titanium, chromium, rhodium, iron, cobalt, nickel, nitrides, silicon nitrides, boron nitrides, cubic boron nitrides, natural diamonds, synthetic diamonds, cemented carbide, spherical carbides, low-alloy sintered materials, cast carbides, silicon carbides, boron carbides, cubic boron carbides, molybdenum carbides, titanium carbides, tantalum carbides, niobium carbides, chromium carbides, vanadium carbides, iron carbides, tungsten carbides, macrocrystalline tungsten carbides, cast tungsten carbides, crushed sintered tungsten carbides, carburized tungsten carbides, steels, stainless steels, austenitic steels, ferritic steels, martensitic steels, precipitation-hardening steels, duplex stainless steels, ceramics, iron alloys, nickel alloys, cobalt alloys, chromium alloys, HASTELLOY® alloys (e.g., nickel-chromium containing alloys, available from Haynes International), INCONEL® alloys (e.g., austenitic nickel-chromium containing super alloys available from Special Metals Corporation), WASPALOYS® (e.g., austenitic nickel-based super alloys), RENE® alloys (e.g., nickel-chromium containing alloys available from Altemp Alloys, Inc.), HAYNES® alloys (e.g., nickel-chromium containing super alloys available from Haynes International), INCOLOY® alloys (e.g., iron-nickel containing super alloys available from Mega Mex), MP98T (e.g., a nickel-copper-chromium super alloy available from SPS Technologies), TMS alloys, CMSX® alloys (e.g., nickel-based super alloys available from C-M Group), cobalt alloy 6B (e.g., cobalt-based super alloy available from HPA), N-155 alloys, any mixture thereof, and any combination thereof. In some embodiments, the reinforcing particles may be coated. In some cases, multiple types of reinforcing particles may be used to form a single resulting drill bit.

The binder-reinforcing material may comprise a metal, alloy, intermetallic, ceramic, or any combination thereof. The binder-reinforcing material may have various sizes and shapes according to the selected localized properties and/or the selected diffusion rates of binder-reinforcing material. The binder-reinforcing material may be placed in a variety of configurations, based on the selected properties and/or the size of the region over which the localized properties are to be spread.

At step 304, the manufacturer may optionally place the binder-reinforcing material among the reinforcing particles at selected locations within the matrix bit body mold. The binder-reinforcing material may be layered and/or mixed with the reinforcement particles. The placement of the binder-reinforcing material in select locations may provide localized properties.

At step 306, the manufacturer may optionally determine whether there is another selected location where the binder-reinforcing material should be placed. If there is another selected location where the binder-reinforcing material should be placed, method 300 may return to step 304 and place the binder-reinforcing material in the next selected location, otherwise method 300 may proceed to step 308. Steps 302 and 304 may occur simultaneously until the matrix bit body mold has been filled.

At step 308, the manufacturer places the universal binder material in the matrix bit body mold. Depending upon the application, the manufacturer may by-pass the steps 304 and 306 and go directly to step 308 given that the universal binder in accordance with the present disclosure has enhanced performance properties as compared to convention universal binders. The universal binder material may be placed in the mold after the reinforcement particles (and where used, the binder-reinforcing material) have been packed into the mold. The universal binder material may include the copper manganese nickel alloy described further below in accordance with the present disclosure. The universal binder material and/or the localized binder material may be selected such that the downhole temperatures during the subterranean operation are less than the melting point of the universal binder material, the localized binder material, and/or any alloy formed between the universal binder material and the localized binder material.

At step 310, the manufacturer may heat the matrix bit body mold and the materials disposed therein via any suitable heating mechanism, including a furnace. When the temperature of the universal binder material exceeds the melting point of the universal binder material, the liquid universal binder material may flow into the reinforcement particles.

At step 312, as the universal binder material infiltrates the reinforcing particles, the universal binder material may additionally react with and/or diffuse into any binder reinforcing material that is used. In some reactions, the reaction between the universal binder material and the binder-reinforcing material may form an intermetallic material composition. In other reactions, the reaction between the universal binder material and the binder-reinforcing material may form a stiff alloy composition.

At step 314, the manufacturer may cool the matrix bit body mold, the reinforcing particles, binder-reinforcing material (if used), and the universal binder material. The cooling may occur at a controlled rate. After the cooling process is complete, the mold may be broken away to expose the body of the resulting drill bit. The resulting drill bit body may be subjected to further manufacturing processes to complete the drill bit.

The above method identifies one exemplary method of forming the matrix bit body. There are several possible embodiments, based on material selection and design, e.g., melting or not of any binder-reinforcing material that may be used, formation of intermetallic particles before or during infiltration or during a heat treatment cycle after infiltration, whereby the reinforced binder zones may be formed.

The details of the universal binder in accordance with the present disclosure will now be described. The binder in accordance with the present disclosure is the part of the metal matrix composite that fills in the space between the reinforcing particles, holding them together and allowing transmission of stress across the material. It also adds toughness to the system (as opposed to a monolithic carbide material), inhibiting crack propagation caused by stresses experienced during drilling. The binder should also impact a measure of erosion resistance. Typically, the hardness of a material is indicative of its ability to resist erosion. Binder, being soft comparted to the reinforcing carbide powder, is more susceptible to erosive loss during drilling. Improving the erosion resistance of the binder without sacrificing toughness would improve bit life. Increasing the strength of the binder would also serve to reduce incidents of cracking during manufacturing of while drilling.

Conventional universal binders comprise 50% Cu, 25% Mn, 15% Ni, and 10% Zn, and are known as MF53. Using the material properties of MF53 with D63 as a baseline, the universal binder in accordance with the present disclosure was arrived at by increasing the manganese content to 30% and nickel to 25%. The zinc component was eliminated in favor of the increased manganese and nickel content. The increased manganese and nickel provides a transverse rupture strength (TSR) increase of approximately 5.5% as well as an improved resistance to erosion. The removal of the zinc and addition of manganese is believed to be the reason behind the observed increase in strength. The small increase in nickel also resulted in an increased number of MnNi inter-metallic particles. The addition of these inter-metallic particles is believed to improve the binder's erosion resistance. The formation of the MnNi inter-metallic particles serves to improve the erosion resistance of the binder alloy and thus the overall erosion resistance of the MMC. These inter-metallic particles reinforce the binder, reducing the effects of erosion by slowing the rate at which reinforcing particles are lost from the material surface during drilling.

In order for the universal binder to achieve the improved performance characteristics described herein, the binder may have anywhere between 30-40% Mn and 10-30% Ni with copper as the balance. These percentages recited herein are weight percent (wt %). Such compositions are believed to yield a good ratio of inter-metallic particles and solid solution strengthening. The addition of larger concentrations of manganese and nickel would depress the melt temperature of the binder. Removal of the zinc is also believed to reduce chemical attack of the blank, reduce the formation of detrimental inter-metallic particles found in the binder rich region, and allow more consistent solidus and liquidus points, which limits detrimental coring effects during solidification.

The universal binder in accordance with the present disclosure improves bit life by reducing the formation of cracks and improving the erosion resistance of the bit. The manufacturing process of the bit would also be less prone toward forming defects during the multiple heating and cooling cycles seen in the process.

FIG. 4 is a schematic drawing in section with portions broken away showing an example of a mold assembly used in forming the body in accordance with the present disclosure. Mold assembly 400 may include mold 470, gauge ring 472, and funnel 474 which may be formed of any suitable material, such as graphite. Gauge ring 472 may be threaded to couple with the top of mold 470 and funnel 474 may be threaded to couple with the top of gauge ring 472. Funnel 474 may be used to extend mold assembly 400 to a height based on the size of the drill bit to be manufactured using mold assembly 400. The components of mold assembly 400 may be created using any suitable manufacturing process, such as casting, sintering and/or machining. The shape of mold assembly 400 may have a reverse profile from the exterior features of the drill bit to be formed using mold assembly 400 (the resulting drill bit).

In some cases, various types of temporary displacement materials and/or mold inserts may be installed within mold assembly 400, depending on the configuration of the resulting drill bit. The temporary displacement materials and/or mold inserts may be formed from any suitable material, such as consolidated sand and/or graphite. The temporary displacement materials and/or mold inserts may be used to form voids in the resulting drill bit. For example, consolidated sand may be used to form core 476 and/or fluid flow passage 480. Additionally, mold inserts (not expressly shown) may be placed within mold assembly 400 to form pockets 466 in blade 426. Cutters, including cutters 128 shown in FIG. 2, may be attached to pockets 466, as described with respect to cutter pockets 166 in FIG. 2.

A generally hollow, cylindrical metal mandrel 478 may be placed within mold assembly 400. The inner diameter of metal mandrel 478 may be larger than the outer diameter of core 476 and the outer diameter of metal mandrel 478 may be smaller than the outer diameter of the resulting drill bit. Metal mandrel 478 may be used to form a portion of the interior of the drill bit.

After displacement materials are placed within mold assembly 400, mold assembly may be filled with the reinforcement particles 490. Reinforcing particles may be selected to provide designed characteristics for the resulting drill bit, such as fracture resistance, toughness, and/or erosion, abrasion, and wear resistance. Reinforcing particles may be any suitable material, such as particles of metals, metal alloys, super alloys, intermetallics, borides, carbides, nitrides, oxides, silicides, ceramics, diamonds, and the like, or any combination thereof. As those of ordinary skill in the art will appreciate, multiple types of reinforcing particles 490 may be used.

During the process of loading the reinforcing particles 490 in mold assembly 400, the binder-reinforcing material 492 may optionally be loaded in specific locations and may be layered and/or mixed with the reinforcing particles 490, as described in step 304 of method 300 shown in FIG. 3. The placement of binder-reinforced material 492 in select regions may provide localized properties in those regions where the material is placed. The binder-reinforcing material 492 may be selected based on the diffusion characteristics of the material. A more focused reaction between universal binder material 494 and the binder-reinforced material 492 may be achieved by selecting materials with low inter-diffusion coefficients and relying upon gravity and alloying of the materials during the infiltration process to produce localized properties in the localized regions, for example, only in the reinforced binder pools.

Once the reinforcing particles 490 and binder-reinforcing material 492 are loaded in mold assembly 400, those components may be packed into mold assembly 400 using any suitable mechanism, such as a series of vibration cycles. The packing process may help to ensure consistent density of the reinforcing particles 490 and provide consistent properties throughout the portions of the resulting drill bit formed of such material.

After the packing of reinforcing particles 490 and binder-reinforcing material, universal binder material 494 may be placed on top of these components, core 476, and/or metal mandrel 478. Universal binder material 494 includes the copper manganese nickel alloy described herein. Universal binder material 494 may be selected such that the downhole temperatures during the subterranean operation are less than the critical temperature or melting point of universal binder material 494, binder-reinforcing material 492, and/or any alloy formed between universal binder material 494 and binder-reinforcing material 492.

Mold assembly 400 and the materials disposed therein may be heated via any suitable heating mechanism, including a furnace. When the temperature of universal binder material 494 exceeds the melting point of universal binder material 494, liquid universal binder material 494 may flow into reinforcing particles 490 towards mold 470. As universal binder material 494 infiltrates the reinforcing particles 490, universal binder material 494 may additionally react with and/or diffuse into or infiltrate binder-reinforcing material 492. In some reactions, the reaction between universal binder material 494 and binder-reinforcing material 492 may form an intermetallic material composition. In other reactions, the reaction between universal binder material 494 and the binder-reinforced material 492 may form a stiff alloy composition. The diffusion between universal binder material 494 and binder-reinforcing material 492 may form a functional gradient of properties between the regions of the drill bit containing infiltrated reinforcing particles and regions of the bit containing binder-reinforced zones.

Once universal binder material 494 has infiltrated reinforcing particles 490 and binder-reinforcing material 492, mold assembly 400 may be removed from the furnace and cooled at a controlled rate. After the cooling process is complete, mold assembly 400 may be broken away to expose the body of the resulting drill bit. The resulting drill bit body may be subjected to further manufacturing processes to complete the drill bit. For example, cutters (for example, cutters 128 shown in FIG. 2) may be brazed to the drill bit to couple the cutters to pockets 466. During the brazing process, reinforced binder zones may be heated to a sufficient point to cause additional local diffusion, precipitation of phases, formation of intermetallics, and the like, near pockets 466. Furthermore, a post-manufacture heat treatment may enhance certain properties of the binder-reinforced zones, such as increased diffusion and functional grading of properties, precipitation of phases, formation of intermetallics, and the like. Such heat treatment process(es) may occur at any stage after infiltration, such as during cooling, after cooling, or after attachment of cutters.

The placement of the binder-reinforcing material shown in FIG. 4 is exemplary only. It is also optional given the enhanced performance expected from the improved universal binder in accordance with the present disclosure. The placement of the binder-reinforcing material may be based on the regions of the drill bit needing additional toughness, erosion resistance and other desired localized properties. Additionally, the binder-reinforcing material may be alternatively mixed with the reinforcing material throughout the regions where the reinforcing material is placed or throughout the entire bit.

A drill bit comprising reinforcing particles and a binder comprising copper, manganese and nickel, wherein the manganese content of the binder is about 30-40 wt % is disclosed. In any of the embodiments described in this paragraph, the content of nickel may be about 10-30 wt %. In any of the embodiments described in this paragraph, copper may comprise the balance of the content of the binder. In any of the embodiments described in this paragraph, the manganese content of the binder may be about 30 wt % and the nickel content may be about 25 wt %. In any of the embodiments described in this paragraph, the copper may comprise the balance of the content of the binder. In any of the embodiments described in this paragraph, the binder may be substantially free of zinc.

A drill bit comprising: reinforcing particles, and a binder comprising copper, manganese and nickel and combinations thereof, wherein the manganese content of the binder is about 30 wt % or greater is disclosed. In any of the embodiments described in this paragraph, the nickel content may about 10-30 wt %. In any of the embodiments described in this paragraph, copper may comprise the balance of the content of the binder. In any of the embodiments described in this paragraph, the manganese content of the binder may be about 30 wt % and the nickel content may be about 25 wt %. In any of the embodiments described in this paragraph, copper may comprise the balance of the content of the binder. In any of the embodiments described in this paragraph, the binder may be substantially free of zinc.

A method of forming a drill bit is disclosed. The method comprises: placing reinforcing particles in a mold used in forming a body of the drill bit; placing a binder in the mold, the binder comprising copper, manganese and nickel, wherein the manganese content is about 30-40 wt %.; and heating the mold. In any of the embodiments described in this paragraph, the nickel content may be about 10-30 wt %. In any of the embodiments described in this paragraph, copper comprises the balance of the content of the binder placed in the mold. In any of the embodiments described in this paragraph, the manganese content may be about 30 wt % and the nickel content may be about 25 wt %. In any of the embodiments described in this paragraph, copper may comprise the balance of the content of the binder placed in the mold. In any of the embodiments described in this paragraph, the binder may be substantially free of zinc.

Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present disclosure. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. 

What is claimed is:
 1. A drill bit comprising: reinforcing particles, and a binder comprising copper, manganese and nickel, wherein the manganese content of the binder is about 30-40 wt %.
 2. The drill bit according to claim 1, wherein the content of nickel is about 10-30 wt %.
 3. The drill bit according to claim 2, wherein copper comprises the balance of the content of the binder.
 4. The drill bit according to claim 2, wherein the manganese content of the binder is about 30 wt % and the nickel content is about 25 wt %.
 5. The drill bit according to claim 4, wherein copper comprises the balance of the content of the binder.
 6. The drill bit according to claim 5, wherein the binder is substantially free of zinc.
 7. The drill bit according to claim 1, wherein the binder is substantially free of zinc.
 8. A drill bit comprising: reinforcing particles, and a binder comprising copper, manganese and nickel and combinations thereof, wherein the manganese content of the binder is about 30 wt % or greater.
 9. The drill bit according to claim 8, wherein the nickel content is about 10-30 wt %.
 10. The drill bit according to claim 9, wherein copper comprises the balance of the content of the binder.
 11. The drill bit according to claim 9, wherein the manganese content of the binder is about 30 wt % and the nickel content is about 25 wt %.
 12. The drill bit according to claim 11, wherein copper comprises the balance of the content of the binder
 13. The drill bit according to claim 12, wherein the binder is substantially free of zinc.
 14. The drill bit according to claim 8, wherein the binder is substantially free of zinc.
 15. A method of forming a drill bit comprising: placing reinforcing particles in a mold used in forming a body of the drill bit; placing a binder comprising copper, manganese and nickel and having a manganese content of about 30-40 wt % in the mold; and heating the mold.
 16. The method according to claim 15, further comprising placing a binder having a nickel content of about 10-30 wt % in the mold.
 17. The method according to claim 16, further comprising placing a binder having copper as the balance of the content of the binder in the mold.
 18. The method according to claim 16, further comprising placing a binder having a manganese content of about 30 wt % and a nickel content of about 25 wt % in the mold.
 19. The method according to claim 18, further comprising placing a binder having copper as the balance of the content of the binder in the mold.
 20. The method according to claim 15, further comprising placing a binder which is substantially free of zinc in the mold. 